Homework Problem #3 7

Moderators: Chem_Mod, Chem_Admin

805377003
Posts: 97
Joined: Wed Sep 30, 2020 10:10 pm

Homework Problem #3 7

Postby 805377003 » Sat Jan 16, 2021 11:42 am

At equilibrium, the concentrations in this system were found to be [N2]=[O2]=0.100 M and [NO]=0.600 M.
N2(g)+O2(g)↽−−⇀2NO(g)

If more NO is added, bringing its concentration to 0.900 M, what will the final concentration of NO be after equilibrium is re‑established?

I've attempted this problem but I keep getting it wrong. Can someone walk my through the steps?

IsaacLaw1E
Posts: 94
Joined: Wed Sep 30, 2020 9:58 pm
Been upvoted: 1 time

Re: Homework Problem #3 7

Postby IsaacLaw1E » Sat Jan 16, 2021 11:58 am

You need to make an ICE table. Because you added [NO], there will be more [N2] and [O2] formed, so the reverse reaction occurs.
2NO <-> N2 + O2, and the equilibrium values are [NO] = 0.9 - 2x, [N2] = [O2] = 0.1 + x. The Ka is found with the given equilibrium concentrations, so Ka = (0.1)(0.1)/(0.6^2) = 0.028

ALee_1J
Posts: 109
Joined: Wed Sep 30, 2020 9:32 pm

Re: Homework Problem #3 7

Postby ALee_1J » Sat Jan 16, 2021 11:59 am

Using [N2]=[O2]=0.100 M and [NO]=0.600 M, calculate the Ka value. This value will allow you to calculate the values at equilibrium should the reaction be disturbed. Then solve an ICE table with the values [N2]=[O2]=0.100 M and [NO]=0.900 M for the initial concentration. Reminder: solving for x doesn't always mean that that's the final concentration of a substance at equilibrium.

George Hernandez 3I
Posts: 80
Joined: Wed Sep 30, 2020 9:52 pm

Re: Homework Problem #3 7

Postby George Hernandez 3I » Sat Jan 16, 2021 12:05 pm

Like the others said, solving for x means finding the unknown changes to the concentrations. Remember that K will always stay the same, with the exception of temperature change. So by adding more product, some of that product will decompose/form to more reactants until it reaches the product/reactant ratio again.


Return to “Equilibrium Constants & Calculating Concentrations”

Who is online

Users browsing this forum: No registered users and 4 guests